Grounding Questions, Electrical

[skipmarcy]

My Generac generator bought new in 2019 has the grounding lug on the frame - I use a #6 copper wire from it to my ground rod in the ground below my electric meter - just use a pair of vise-grips to attach the wire to the top of the rod.

 

[grsthegreat]

generac did away with the grounding lug back around 2015ish. They even put out a statement to the fact not to use a ground at generator, as it created a separately derived grounding situation. Basically they redesigned their systems to ground thru building wires. I’m surprised your 2019 unit had one.

 

[ponytug]

Doesn't it depend on the details of how the generator is constructed and how it is wired in? If you are interested, you can see OSHA's fact sheet here.

I have to admit, I follow the logic of not wanting ground loops, and why you wouldn't want ground currents traveling through conduits, but I have seen out buildings treated both to separate ground rods, and ground wires derived from the main panel.

Caveat: I am not an electrician and don't play one on TV! I don't know the current NEC regulations at all well. I have seen well thought out opinions by "experts" go both ways. Certainly one interpretation of the post 2008 electrical code has a ground loop design, others don't.

Anyone who is an expert care to weigh in?

All the best,

Peter

 

[Diggin It]

Doesn't it depend on the details of how the generator is constructed and how it is wired in?

Anyone who is an expert care to weigh in?

GRS is a factory trained rep for Generac with decades of experience on many of their models. When it comes to 'expert' on generator installations, you won't find another here on this board that can exceed that.

Mine has #6 from the generator to the ATS that is tied to the main panel and meter which are tied to two ground rods, all within 15' of each other. I just wasn't sure if a third ground rod tied to the first two would either help or hurt

As far as grounding in general, one of the lineman here on the board may have some additional comments.

 

[skipmarcy]

My Generac is a portable unit and I use it exclusively with extension cords only - the ground lug wired to the house's ground rod is the only ground the whole system has - I do not have any interface with the house wiring at all.

 

[grsthegreat]

Ah…portable. That’s a whole different thing. Portable generators still come with ground lugs, because they are generally used remotely to power equipment and not tied into a house system. I was referring to standby units not needing grounding rods.